Although geographic isolation is a leading driver of speciation, the tempo and pattern of divergence at the genomic level remain unclear. We examine genome-wide divergence of putatively single-copy orthologous genes (POGs) in 20 allopatric species/variety pairs from diverse angiosperm clades, with 16 pairs reflecting the classic eastern Asia-eastern North America floristic disjunction. In each pair, >90% of POGs are under purifying selection, and <10% are under positive selection. A set of POGs are under strong positive selection, 14 of which are shared by 10-15 pairs, and one shared by all pairs; 15 POGs are annotated to biological processes responding to various stimuli. The relative abundance of POGs under different selective forces exhibits a repeated pattern among pairs despite an ~10-million-year difference in divergence time. Species divergence times are positively correlated with abundance of POGs under moderate purifying selection, but negatively correlated with abundance of POGs under strong purifying selection.
Sequences of ortologous gene families and pairs of POGs sequences used for calculation of Ka and Ks have been submitted to Dryad (https://datadryad.org//). Raw transcriptome data have been submitted to NCBI SRA database with Bioproject number PRJNA508825 and Biosample number from SAMN10534244 to SAMN10534283 (Supplementary File 11).
Natural selection and repeated patterns of molecular evolution following allopatric divergenceBioproject number PRJNA508825 and Biosample number from SAMN10534244 to SAMN10534283.
Data from: Natural selection and repeated genome-wide patterns of molecular evolution following allopatric divergenceDryad Digital Repository, 10.5061/dryad.f1f0q44.
- Yibo Dong
- Wenbin Zhou
- Jenny Xiang
- Shichao Chen
- Pamela S Soltis
- Douglas E Soltis
- Shichao Chen
- Yun-peng Zhao
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
- Daniel J Kliebenstein, University of California, Davis, United States
© 2019, Dong et al.
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